1. Field of the Technology
The present application relates generally to torque power tools, and more particularly to reaction adaptors for tools, tools having adaptors, and methods of using the same.
2. Description of the Related Art
Torque power tools are known in the art and include those driven pneumatically, electrically, hydraulically, manually, by a torque multiplier, or otherwise powered. All torque power tools have a turning force and an equal and opposite reaction force. Often this requires the use of reaction fixtures to abut against viable and accessible stationary objects to stop the housing of the tool from turning backward, while a fastener, such as for example a nut, turns forward. The stationary object must be viable in that it must be able to absorb the reaction force and be accessible in that it must be nearby for the reaction fixture to abut against it. The reaction fixture may be connected around an axis or the housing, and a mechanism is provided to hold the fixture steady relative to the tool housing during operation. This may be achieved with splines, polygons, or other configurations. Several examples of known torque power tools that include a reaction arm to abut against a stationary object are disclosed in U.S. Pat. Nos. 6,152,243, 6,253,642 and 6,715,881, commonly owned and incorporated by reference herein.
Present reaction fixtures limit tool functionality. Those connected about a turning force axis, on the one hand, allow for complete rotation of a tool housing about the turning force axis without changing the abutment point. On the other hand, they are limited to coaxial abutment against stationary objects. Those connected at the housing, on the one hand, allow for abutment against stationary objects positioned in various circumferential and spatial locations relative to the nut to be turned. On the other hand, they prevent complete rotation of the tool housing about the turning force axis without changing the abutment point.
Adjustability of present reaction fixtures is limited to about a single axis which precludes the use of a single tool in assemblies having viable stationary objects in non-accessible locations. Operators commonly need several tools at a workstation each having a reaction fixture oriented differently to abut against a viable and accessible stationary object. Alternatively, operators must disassemble the tool, reposition the reaction fixture and reassemble the tool. The former solution is expensive while the latter solution is time consuming.
If present reaction fixtures cannot abut against viable and accessible stationary objects properly, custom reaction fixtures need to be engineered. Re-engineering of the tool connection means to accommodate custom reaction fixtures is prohibitively expensive, unsafe and time consuming. Tool manufacturers offer several commercially available reaction fixture constructions for these reasons.
During operation of tools, twisting forces are induced on the housing along the turning force axis by the transfer of the reaction force through the reaction fixture to the stationary object. The reaction force for tools with torque output of 10,000 ft. lbs. can be as high as 40,000 lbs. and is applied as a side load to the stationary object in one direction and to the fastener to be turned in an opposite direction. Large reaction forces bend and increase the turning friction of the fastener.
Twisting forces are limited and least destructive when the reaction force is transferred to a stationary object perpendicular to the turning force axis. The ideal abutment point is perpendicular to the turning force axis and on the same plane as the fastener to be turned. Tools operating with sockets that reach down to the same plane as the fastener cause twisting forces. Twisting forces exacerbate fastener-bending forces roughly by a distance H between the attachment point of the socket to the tool and the fastener plane. These twisting and fastener-bending forces are limited and least destructive when the reaction force is transferred perpendicular to the turning force axis in a plane roughly the distance H above the fastener plane. Thus the ideal abutment pressure point is perpendicular to the turning force axis in the plane distance H above the fastener plane. Rarely do present reaction fixtures transfer the reaction force to the ideal abutment pressure point. Reaction fixtures must be adjustable to minimize twisting and fastener-bending forces so as to avoid the tool from jumping off of the job or from failing.
Present reaction fixtures are not adjustable around multiple axes due to concerns regarding total tool weight. Tools need to be portable for the majority of fasteners. The maximum tool weight to be carried safely by an operator should not exceed 30 lbs. For larger fasteners, the maximum tool weight to be carried safely by two operators should not exceed 60 lbs. For applications where the only viable and accessible stationary object requires custom reaction fixtures, these weights are exceeded and crane use is required. Crane use to support the tool is expensive and is economical only for large fasteners.
Other tools provided with reaction fixtures of the prior art are disclosed, for example, in U.S. Pat. Nos. 3,361,218, 4,549,438, 4,538,484, 4,507,546, 4,619,160, 4,671,142, 4,706,526, 4,928,558, 5,027,932, 5,016,502, 5,142,951, 5,151200, 5,301,574, 5,791,619, 6,260,443.
Accordingly, what are needed are reaction force transfer mechanisms which overcome the deficiencies of the prior art, as well as methods of using the same.